Firmware Manual

Table Of Contents
40 Program features
External controller interface
General
The drive can be connected to an external controller (such as the ABB AC 800M)
using either fiber optic or twisted-pair cable. The ACS880 is compatible with both the
ModuleBus and DriveBus connections.
Topology
An example connection with either a ZCU-based or BCU-based drive using fiber optic
cables is shown below.
Drives with a ZCU control unit require an additional FDCO DDCS communication
module; drives with a BCU control unit require an RDCO or FDCO module. The BCU
has a dedicated slot for the RDCO – an FDCO module can also be used with a BCU
control unit but it will reserve one of the three universal option module slots. Ring and
star configurations are also possible much in the same way as with the
master/follower link (see section Master/follower functionality on page 33); the
notable difference is that the external controller connects to channel CH0 on the
RDCO module instead of CH2. The channel on the FDCO communication module
can be freely selected.
The external controller can also be wired to the D2D (RS-485) connector using
shielded, twisted-pair cable. The selection of the connection is made by parameter
60.51 DDCS controller comm port.
Communication
The communication between the controller and the drive consists of data sets of three
16-bit words each. The controller sends a data set to the drive, which returns the next
data set to the controller.
The communication uses data sets 10…33. The contents of the data sets are freely
configurable, but data set 10 typically contains the control word and one or two
references, while data set 11 returns the status word and selected actual values. For
T = Transmitter; R = Receiver
ACS880
(BCU) Control unit
RDCO
CH0
Controller
RT
RT
ACS880
(ZCU) Control unit
FDCO
RT